1. Field of the Invention
The present invention is generally directed to the field bearing hubs and support bearings for supporting rotating machinery or members and, in preferred embodiments to wheel bearing hubs and axle assemblies used on vehicles including all types of automobiles, trucks, trailers, aircraft, farm equipment and the like. The teachings of the invention also are applicable to other environments such as industrial machinery and the like. More particularly, the invention is directed to visual emergency warning indicators which reflect when bearings have become loose or the bearings and related components have become dangerously worn which could result damage to equipment, machinery and vehicles. With vehicles, such wear or failure can result in wheel bearing hub, axle or axle spindle damage that may cause the wheel bearing hub, brake drum, wheel(s) and tire(s) to separate from the vehicles. In some embodiments of the invention, the visual emergency warning indicators may also provide a visual indication of excessive heat build up within a wheel or other bearing hub that could result in bearing damage and hub mounting failure that could also result in damage, and in vehicles, to possible wheel separation.
The invention is also directed to providing enlarged high strength steel early warning jam nuts that can be easily installed using conventional tools and which, should the wheel or other hub bearings begin to fail, can prevent wheel assembly, or other component, separation for a period of time to allow corrective action to be taken. The invention also provides locks for the early warning jam nuts to prevent accidental loosening of the jam nuts.
2. Brief Description of the Related Art
A particular problem associated with substantially any type of vehicle that has wheels mounted on bearings, including commercial and non commercial vehicles is a sudden and unexpected separation of one or more wheel assemblies from a non driven axle spindle or driven axle drive tube spindle to which they are mounted. Such separations are brought about by bearing failures, hub failures and bearing hub assembly retaining failures. Such failures may be caused by many problems including bearing assembly wear, lack of lubrication and loosening of jam or lock nuts used to secure the bearing assemblies in safe operative condition. When a failure of an outer bearing assembly occurs, the bearings can destroy the integrity of the lock and jam nuts such that it is possible that the wheel hub can thereby become separated from the axle spindle or drive tube spindle. The separation of a wheel bearing hub from a vehicle traveling at any speed creates a potentially catastrophic situation. Considering that an average two wheel bearing hub includes two rims, two tires and a brake drum that can have a combined weight of 400 or more pounds, if a wheel bearing hub of a truck separates at a speed of 55 mph or greater, not only is there probable loss of vehicle control that can result in possible injury or death, but the wheel assembly itself can become a damaging or lethal projectile as it careens into oncoming or other vehicular traffic or into pedestrians. Such possible tragedies are caused not only by the inherent conventional wheel bearing hub designs, and/or mounting techniques, which are in conventional use, but also due to poor or improper maintenance.
Currently, it is virtually impossible for a driver or federal or state Department of Transportation inspector to inspect wheel bearings and locking mechanisms unless the wheel bearing hub cover is removed or the drive axle is removed. Prior to removal of these components, the lubricant must be removed from the bearing cavity and collected. Such a practice is usually not performed during motor vehicle inspections, nor is rarely performed by drivers or operators. As a practical matter, many wheel, or other machinery, bearing hubs are not checked or inspected until vehicle or equipment maintenance is required and then, all too often, these areas can be overlooked unless extensive maintenance is performed such as changing brake components, leaky seals or the like.
With reference to FIGS. 1 and 2, a wheel bearing hub 10 is shown as conventionally mounted to freely rotate about a spindle 11 of a non-driven axle 12, such as one associated with a commercial trailer. The spindle includes a threaded end portion 13. The hub is seated about a bearing assembly that includes inner tapered roller bearings 14 and outer tapered roller bearings 16. The hub includes an inner cavity or bearing housing 17 that forms a lubricant reservoir to retain oil that fills the lower portion of the cavity to a level below a removable plug 18 that normally seals an opening 19 of a wheel bearing hub cover 20. The wheel bearing hub cover seals the cavity using a gasket, not shown, and the cover is secured using bolts 21 that pass through openings in an outer flange 22 of the hub 10 and are threaded into threaded openings 23 in an outer face 24 of the hub. The inner and outer tapered bearings 14 and 16 are seated between inner and outer tapered bearing journals 25 and 26 and 27 and 28, respectively. The bearing assembly is sealed opposite the wheel hub cover by an inner oil seal 29.
The inner and outer bearings 14 and 16 are designed to be retained in place on the spindle by a combination of an inner nut 30, a lock washer 31 and a locknut or jam nut 32. During assembly, a wrench is used to thread the inner nut 30 on the threaded end 13 of the spindle 12. Thereafter, lock washer 31 is placed over the end of the spindle. To prevent the nut from loosening, the nut may include a tab or nubbin 33 that cooperatively seats within one of a plurality of holes 34 that are provided in spaced relationship about the body of the lock washer 31. The washer may also include a locking tab 35 that extends inwardly thereof that is cooperatively seated within a channel or keyway 36 formed or machined in the threaded end portion 13 of the spindle 11. With the lock washer in place, the jam nut 32 is threaded to the threaded end portion of the spindle and tightened to retain the bearing assembly in place.
Conventional designs for wheel bearing hubs and axle spindles or drive tube spindles rely solely on the integrity of the outer bearings and current locking methods to maintain the wheel bearing hubs in proper position on the spindles and to prevent failures resulting in wheel separation. Should the outer bearings fail or the jam nuts used to retain the wheel bearing hubs on the bearings fail, there is no provision for preventing separation of the wheel bearing hub assembly. If a total failure of the outer bearing occurs, the locking components including the inner nut 30, the lock washer 31 and the jam nut 32 are small enough in size and diameter relative to the diameter of the hub bearing housing that the hub can wobble over or “walks” over the locking members and become completely separated from the spindle. In addition, the size and thickness of current jam nuts is such as to make it difficult to tighten or remove the jam nuts. Conventional jam nuts are formed of steel of no more than ¼″ in thickness and are varied in size. Because of this, special tools are required in a variety of sizes, and if not available, mechanics can damage the jam nuts using improper tools, such as a hammer and chisel, which can damage and lead to failure of the jam nuts.
There is no provision in the prior art of providing an instant visual warning that there is damage within the wheel bearing hub causing the wheel bearing hub to oscillate, wobble or not rotate as it should which suggests that the bearings may be worn or damaged or that the locking components are no longer applying sufficient force to retain the bearings in place. As there is no early warning, it is not possible for a driver or operator to know that corrective action must be taken to prevent further damage and accidental wheel separation.
In addition to the foregoing and especially along the left side of a vehicle where the rotational direction of the wheels in a forward direction is counterclockwise, the locknuts, which are applied in a clockwise direction, can become loose. If there is any loosening of a locknut, a wobble and/or oscillation will develop between the wheel bearing hub and the spindle that will result in damage to and possible destruction of the bearings and/or bearing hub locking members resulting in wheel assembly separation.
A further problem associated with conventional wheel and other bearing hub assemblies is the monitoring of lubricant level. In some prior art structure, the driver or mechanic must remove a rubber plug and judge the lubricant level by touch or by inserting a gauge device, stick, screwdriver or the like. As the plugs are retained in place by friction fit, they will often leak and become messy. In the prior art structure shown in FIGS. 1 and 2, to provide a more user friendly manner of determining correct lubricant levels, the outer face 37 of the cover is formed of a transparent plastic material so that a visual check can be made of the lubricant level. Unfortunately, the plastic becomes discolored by the lubricant in a very short period of time making visual inspection very difficult.
In view of the foregoing, there remains a need to provide for added safety in the field of the design and construction of vehicle wheel bearing hubs and other bearing hub and bearing housings and bearing assemblies, that will provide drivers, transportation officials, safety inspectors or other observers and operators an early indication that a problem exists in a bearing hub or that conditions therein are indicative of a possible failure that requires immediate attention in order to protect operators, drivers, passengers, pedestrians and property from harm, injury or death.
There is also a need to provide a system for securing wheel bearing hubs to spindles or drive tube spindles in such a manner that it is not necessary to maintain numerous specialized tools on hand and such that conventional tools may be used and wherein it is not possible for wheel bearing hubs to simply grind down and wobble over the locking components thereby resulting in wheel bearing hub separation from spindles or drive tube spindles associated with the vehicle axles.